Marijuana One of the best-known hallucinogens is marijuana. “Most people have hallucinations at one time or another, although they do not know when to expect them. Some people, however, have them on purpose. They do so by taking certain drugs called hallucinogens (Mann 48). No one knows exactly when the use of marijuana was first began, although they have found reference to its mind altering effects. One of the first references to marijuana was in the 28th century, when a Chinese Emperor Shen Nung recommended the medicinal properties of the drug. He recommended its use to relieve female weakness, gout, rheumatism, malaria, beriberi, constipation, and absent